Abstract: Compressor rotor structure and methodology for harmonizing compressor aerodynamics and rotordynamics are provided. Disclosed embodiments benefit from a compressor design effective for improving rotordynamics (e.g., stiffer rotor structure) without reducing a usable aerodynamics range of the compressor. This design may involve variation of the rotor structure along the rotor axis to locate respective surfaces defined by respective inlets of the one or more impellers at a varying distance relative to the rotor axis based on respective ratios selected for the configuration of the impeller bodies. This arrangement may be effective for improving rotordynamics while satisfactorily meeting the respective varying aerodynamics requirements at the various compression stages by the impeller bodies.

Abstract: The present application discloses playback devices and networks, software for operating playback devices and playback device networks, and methods of operating playback devices and networks, where an individual network device is configured to switch between operating various operating modes comprising a non-paired mode and a paired mode, where the playback device is configured to output various channels of audio content within various audio frequency ranges while operating in the various operating modes.

Abstract: A disk is manufactured having a reduced capacity based on a quantity of addressable and non-addressable portions. The method of formatting the disk comprises identifying a first quantity of the storage portions; and labeling the first quantity of storage portions as non-addressable storage portions such that the non-addressable storage portions cannot be accessed by a user or a disk drive. The first quantity of storage portions may include addressable portions designated as non-addressable portions.

Abstract: A system and methods for providing offset information on a storage medium are provided by writing at least one unalterable mark on the storage medium during a manufacturing formatting process. The unalterable mark(s) are variably offset from a fixed position. The amount of offset represents a first source of unique information. The unalterable mark(s) themselves comprise a second source of information. Both sources of information are combinable and may be utilized in connection with the generation of a unique serial number for the storage medium or for other digital rights management purposes.

Abstract: A system and methods for providing offset information on a storage medium are provided by writing at least one unalterable mark on the storage medium during a manufacturing formatting process. The unalterable mark(s) are variably offset from a fixed position. The amount of offset represents a first source of unique information. The unalterable mark(s) themselves comprise a second source of information. Both sources of information are combinable and may be utilized in connection with the generation of a unique serial number for the storage medium or for other digital rights management purposes.

Abstract: A disk is manufactured having a reduced capacity based on a quantity of addressable and non-addressable portions. The method of formatting the disk comprises identifying a first quantity of the storage portions; and labeling the first quantity of storage portions as non-addressable storage portions such that the non-addressable storage portions cannot be accessed by a user or a disk drive. The first quantity of storage portions may include addressable portions designated as non-addressable portions.